NRCS EXIGENT STREAM BANK STABILIZATION
S2O Design provided design and construction management services for the emergency watershed protection project in Lyons, Colo. The project was sponsored by the Town of Lyons and funded by the Natural Resources Conservation Service (NRCS), Colorado Department of Emergency Management, and the property owners.
NRCS classified several sites along the St. Vrain River as exigent sites in need of immediate attention to prevent further, future damage to private properties. S2O Design provided designs to protect from flows up to a 25 year return flow for seven properties in Lyons. After the first runoff season, where flows peaked between a five and 10-year return flow, the streambank stabilizations performed as expected. This project was one of the first permanent flood recovery projects to be construction in Lyons.
To accomplish the project objectives, the design aimed to remove large, channel blocking flood debris and stabilizing streambanks with a combination of rock and bioengineering techniques. The rockwork was covered with topsoil and an erosion control blanket. The banks were seeded and trees and willow stakes were placed intermittently throughout the sites. The project includes approximately 450 feet of streambanks on seven private properties.